The present invention relates to a unit for driving a luminescent display panel using a capacitive luminescent element, such as an organic electro-luminescent element.
As a display which attains low power dissipation, high-quality display, and lower profile, an electro-luminescent display, in which a plurality of organic electro-luminescent elements are arranged in a matrix pattern, has attracted attention. As shown in FIG. 1, the organic electro-luminescent element is formed by means of stacking, on a transparent substrate 100 such as a glass plate on which a transparent electrode 101 is formed, at least one organic function layer 102 which is made up of an ion transport layer, a light-emitting layer; and a positive hole transport layer, and a metal electrode 103. A positive voltage is applied to the anode of the transparent electrode 101, and a negative voltage is applied to the cathode of the metal electrode 103. A d.c. current is applied across the transparent electrode 101 and the metal electrode 103, wherewith the organic function layer 102 illuminates. Use of an organic compound which can be expected to exhibit a superior luminous characteristic embodies a practicable electro-luminescent display.
The organic electro-luminescent element (hereinafter referred to simply as an xe2x80x9cEL elementxe2x80x9d) can be electrically expressed as an equivalent circuit shown in FIG. 2. As can be seen from the drawing, the EL element can be replaced with a capacitive component C and a diode component E which is connected in shunt with the capacitive component and has a diode characteristic. For this reason, the organic electro-luminescent element is considered to be a capacitive luminescent element. When a light-emitting d.c. drive voltage is applied across electrodes of the organic electro-luminescent element, electric charge is stored in the capacitive component C. When the light-emitting d.c. drive voltage exceeds a barrier voltage or threshold illumination voltage unique to the EL element, an electric current starts flowing from the electrode (i.e., the anode of the diode component E) to the organic function layer, which also acts as a light-emitting layer, whereupon the organic electro-luminescent element illuminates at an intensity proportional to the electric current.
As shown in FIG. 3, the characteristic of the EL element concerning a voltage V, a current I, and luminance L is analogous to that of a diode. The current I is considerably small at a voltage lower than the threshold illumination voltage Vth and abruptly increases at a voltage higher than the threshold illumination voltage Vth. The electric current I is substantially proportional to the luminance L. When a drive voltage exceeding the threshold illumination voltage Vth is applied to the EL element, the EL element illuminates at an intensity proportion to the electric current corresponding to the drive voltage. If the drive voltage to be applied to the EL element is below the threshold illumination voltage Vth no drive current flows through the EL element, and hence the luminous intensity of the EL element remains substantially zero.
A passive matrix drive method has hitherto been known as a method of driving a luminescent display panel using a plurality of EL elements. FIG. 4 shows an example structure of a driver device of passive matrix drive type for driving a luminescent display panel. In a luminescent display panel, xe2x80x9cnxe2x80x9d cathode lines (i.e., metal electrodes) B1 to Bn are arranged in parallel with each other so as to extend in the lateral direction, and xe2x80x9cmxe2x80x9d anode lines (i.e., transparent electrodes) A1 to Am are arranged in parallel with each other so as to extend in the longitudinal direction. In respective intersections (a total number of xe2x80x9cnxc3x97mxe2x80x9d) between the cathode lines and the anode lines, light-emission layers of EL elements E1 to Em are sandwiched. The EL elements E1 to Em, which serve as pixels, are arranged in a matrix pattern and are positioned in respective intersections between the anode lines A to Ah and the cathode lines B1 to Bn. One end of the EL element (i.e., the anode of the diode component E of the equivalent circuit) is connected to the anode line, and the other end of the EL element (i.e., the cathode of the diode component E of the equivalent circuit) is connected to the cathode line. The cathode line is connected to and activated by a cathode line scanning circuit 1, and the anode line is connected to and activated by an anode line drive circuit 2.
The cathode line scanning circuit 1 has scan switches 51 to 5n assigned to respective cathode lines B1 to Bn for determining respective electric potentials thereof. Each of the scanning switches 51 to 5n connects to a corresponding cathode line either a reverse bias voltage (e.g., 10 volts) produced from a supply voltage, or a ground potential (e.g., 0 volt).
The anode drive circuit 2 has current sources 21 to 2m(e.g., constant-current sources) for supplying a drive current to respective EL elements, and drive switches 61 to 6m, which are assigned to the anode lines A1 to Am. The drive switches 61 to 6m supply a current to the respective anode lines A1 to An by means of switching operations. A voltage source, such as a constant-voltage source, can be used as a drive source. The previously-described current-luminance characteristic is stable against temperature variations, whereas a voltage-luminance characteristic is unstable against temperature variations. For this reason, a current source (a source circuit which is to be controlled such that the amount of supply current assumes a desired value) is commonly used. The amount of current supplied from current sources 21 to 2m is the amount of current required for sustaining a state in which an EL element illuminates at desired instantaneous luminance (this state will hereinafter be referred to as a xe2x80x9csteady luminous statexe2x80x9d). When the EL element is in a steady luminous state, electric charge corresponding to the amount of supply current is charged into the capacitive component C of the EL element. The voltage across the EL element assumes a specified value Ve corresponding to instantaneous luminance (hereinafter referred to as a xe2x80x9cspecified illumination voltagexe2x80x9d).
The anode lines A1 to Am are connected to an anode line reset circuit 3. The anode line reset circuit 3 has shunt switches 71 to 7m assigned to respective anode lines A1 to Am. The anode lines A1 to Am are brought into ground potential by means of selection of the shunt switches 71 to 7m. The cathode line scanning circuit 1, the anode line drive circuit 2, and the anode line reset circuit 3 are connected to an illumination control circuit 4.
The illumination control circuit 4 controls the cathode line scanning circuit 1, the anode line drive circuit 2, and the anode line reset circuit 3, to thereby display a video in accordance with a video signal supplied from an unillustrated video signal generation system. The illumination control circuit 4 sends a scanning line selection control signal to the cathode line scanning circuit 1, to thereby perform operations for selecting a cathode line corresponding to a horizontal scanning period of a video signal and setting the thus-selected cathode line to ground potential. The scanning switches 51 to 5n are switched so as to apply a reverse bias voltage Vcc to the remaining cathode lines. The reverse bias voltage Vcc is applied from the constant-voltage line connected to the cathode line, in order to prevent illumination of EL elements connected to intersections between the anode line through which a drive current is flowing and cathode lines which are not selected for scanning, which would otherwise be caused by crosstalk. Here, the reverse bias voltage Vcc is usually set equal to the specified illumination voltage Ve. During each horizontal scanning period, the scanning switches 51 to 5n are sequentially switched to ground potential. The cathode line set to ground potential acts as a scanning line which enables illumination of an EL element connected to the cathode line.
The anode line drive circuit 2 controls illumination of the scanning line. The illumination control circuit 4 produces a drive control signal indicating a timing at which and a period of time during which the EL element connected to the scanning line is illuminated in accordance with the pixel information represented by a video signal. In accordance with the drive control signal, the anode line drive circuit 2 switches some of the drive switches 61 to 6m, thereby supplying a drive current to EL elements in accordance with pixel information by way of the anode lines A1 to Am. The EL elements through which the drive current flows illuminate in accordance with the pixel information.
The anode line reset circuit 3 is reset in response to a reset control signal output from the illumination control circuit 4. The anode line reset circuit 4 turns on some of the shunt switches 71 to 7m corresponding to the anode lines, which lines are represented by the reset control signal and are to be reset, and turns off the remaining shunt switches.
Japanese Patent Application Laid-Open No. 232074/1997 filed by the present inventor describes a drive method for a passive matrix luminescent display panel, in which a reset operation is performed for causing discharge of the electric charges stored in each of EL elements arranged into a matrix pattern immediately before scanning lines are switched (the method is hereinafter referred to as a xe2x80x9creset drive methodxe2x80x9d). The reset drive method is for speeding up illumination of an EL element when a scanning line is switched. The reset drive method for a passive matrix luminescent display panel will be described by reference to FIGS. 4 through 6.
Driving operations which will be described hereinbelow and are shown in FIGS. 4 through 6 are directed to a case where, after EL elements E1,1 and E2,1 have been illuminated by means of scanning a cathode line B1, EL elements E2,2 and E3,2 are illuminated by means of scanning a cathode line B2. In order facilitate explanations, illuminating EL elements are depicted by diode symbols, and nonilluminating EL elements are depicted by capacitor symbols. The reverse bias voltage Vcc applied to the cathode lines B1 to Bn is equal to the specified illumination voltage Ve of the EL element; that is, 10 volts.
In FIG. 4, only a scanning switch 51 is switched to a ground potential of 0 volt, thereby scanning the cathode line B1. The reverse bias voltage Vcc is applied to the remaining cathode lines B2 to Bn by way of the scanning switches 52 to 5n. The anode line A1 is connected to a current source 21 by way of a drive switch 61, and the anode line A2 is connected to a current source 22 by way of a drive switch 62. The remaining anode lines A3 to Am are brought into a ground potential of 0 volt by means of shunt switches 73 to 7m. In connection with the circuit diagram shown in FIG. 4, only the EL elements E1,1 and E2,1 are forwardly biased, and a drive current flows into the EL elements E1,1, and E2,1 from respective current sources 21 and 22, as depicted by arrows. As a result, solely the EL elements E1.1 and E2,1 are illuminated. In this state, nonilluminating and hatched EL elements E3,2 to Em,n are charged with a polarity such as that illustrated in the drawing.
The following reset control operation is performed immediately before a scanning operation is performed for causing the next EL elements E2,2 and E3,2 to illuminate from the steady luminous state shown in FIG. 4. Specifically, as shown in FIG. 5, all drive switches 61 to 6m are released, and all the scanning switches 51 to 5n and all the shunt switches 71 to 7m are brought into a ground potential of 0 volt. Further, all the anode lines A1 to Am and cathode lines B1 to Bn are temporarily shunted to a ground potential of 0 volt, thus resetting the entire display. If the entire display is reset, all the anode and cathode lines are brought to a single voltage of 0. The electric charges stored in the EL elements are discharged by way of the route depicted by the arrows provided in the drawing. Thus, all the electric charges stored in the EL elements become momentarily empty.
After the electric charges stored in all the EL elements have been fully discharged, only the scanning switch 52 corresponding to the cathode line B2 is switched to 0 volt, as shown in FIG. 6, thereby scanning the cathode line B2. Simultaneously, the drive switches 62 and 63 are closed, thereby connecting the current sources 22 and 23 to corresponding anode lines. The shunt switches 71 and 74 through 7m are turned on, thus bringing anode lines A1 and A4 through Am to 0 volt.
As mentioned above, according to the reset drive method, illumination is controlled by means of repetition of a scanning mode during which any of the cathode lines B1 to Bn are made active, and a subsequent reset mode. The display is brought into the scanning mode and the reset mode every horizontal scanning period (1H). If the display is brought directly into the state shown in FIG. 6 from the state shown in FIG. 4, the drive current supplied from the current source 23 flows to an EL element E3,2 and is consumed by means of canceling the reverse electric charges (illustrated in FIG. 4) stored in the EL elements E3,3 to E3,n. For these reasons, time is consumed for bringing the EL element E3.2 into a steady luminous state (bringing the voltage across the EL element E3,2 to the specified luminous voltage Ve).
When the above-described reset control operation is performed, the anode lines A2 and A3 assume potentials close to Vcc at the moment at which the scanning line is switched to the cathode line B2. A charge current flows into EL elements E2,2 and E3,2 not only from the current sources 22 and 23 but also from a plurality of routes such as constant-voltage sources connected to cathode lines B1 and B3 to Bn. Parasitic capacitance is charged with the charge current, and the specified luminous voltage Ve is momentarily reached. Thus, the EL elements E2,2 and E3,2 can instantaneously enter a steady luminous state. During a period of time in which the cathode line B2 is scanned, the amount of current supplied from the current source is set to the minimum amount of current required for maintaining the EL element in a steady luminous state at the specified luminous voltage Ve. Therefore, the electric current supplied from the current sources 22 and 23 flows into solely the EL elements E2,2 and E3,2. Thus, all the electric current is dissipated by illumination of the EL elements. As a result, the display is sustained in a luminous state shown in FIG. 6.
As has been described above, according to the known reset drive method, before illumination of the next scanning lines is controlled, all the cathode and anode lines are temporarily connected and reset to a ground potential of 0 volts or a voltage equal to the reverse bias voltage Vcc. Consequently, when the current scanning line has been switched to the next scanning line, there can be speeded up the charging of the EL elements to the specified luminous voltage Ve, as well as the rise and illumination of EL elements, which are connected to the scanning line and are to be illuminated.
As shown in FIGS. 4 and 6, when some cathode lines are scanned by means of application of ground potential thereto, the voltage Vcc is applied to the cathode lines which are not scanned. Further, ground potential is applied to anode lines to which an electric current is not supplied from a current source. More specifically, in the case of the circuit diagram shown in FIG. 4, a reverse bias voltage substantially equal to the voltage Vcc is applied between the anode and cathode of each of the EL elements E3,2 to Em,n. In the case of the circuit diagram shown in FIG. 6, a reverse bias voltage substantially equal to the voltage Vcc is applied between the anode and cathode of each of the EL elements E1,1, E4,1 to Em,1, E1,3 to E1,n, and E4,3 to Em,n. The EL elements to which the reversely-biased voltage Vcc is applied are charged. The thus-charged electric charges are discharged for supplying ground potential to the cathode lines as well as for supplying an electric current from a current source. The electric charges that are charged in and discharged from the EL elements do not contribute to illumination of EL elements at all and are wasted. Power dissipation due to the charging and discharging operations of the EL elements increases in proportion to the number of EL elements. Therefore, useless power dissipation increases as the display area of a display panel increases.
The present invention is aimed at providing a luminescent display panel drive unit capable of diminishing useless power dissipation that does not contribute to illumination.
To this end, the present invention provides a luminescent display panel drive unit including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and connected to the scanning lines and drive lines and which have polarities, the drive unit comprising:
control means for setting a scanning period during which a single scanning line is selected from the plurality of scanning lines in accordance with a scan timing of an input video signal, for specifying a light-emission drive line assigned to the capacitive luminescent element which is connected to the single scanning line and is to be illuminated in accordance with the input video signal during the scanning period, and for setting a reset period during an interval between scanning periods;
scanning means for applying a first potential lower than an illumination threshold voltage of the capacitive luminescent element to the single scanning line during the scanning period, for applying a second potential higher than the illumination threshold voltage to scanning lines other than the single scanning line, and for applying the second potential to all the scanning lines during the reset period; and
drive means for supplying a drive current to the illumination drive line for forwardly applying, during the scanning period, a positive voltage higher than the illumination threshold voltage to the capacitive luminescent element to be illuminated, for applying a third potential slightly lower than the illumination threshold voltage to the drive lines other than the illumination drive line, and for supplying during the reset period a fourth potential equal to the second potential to all the drive lines.
Further, according to the present invention, a first potential lower than an illumination threshold voltage is applied to a single scanning line selected for scanning, during a scanning period. A second potential higher than the illumination threshold voltage is applied to the scanning lines other than the single scanning line. A fourth potential slightly lower than the illumination threshold voltage is applied to the plurality of drive lines other than an illumination drive line connected to capacitive luminescent elements to be illuminated. Consequently, a comparatively-low reverse bias voltage is applied to respective capacitive luminescent elements located in intersections between scanning lines except the single scanning line and drive lines except the illumination drive line. Electric charges which are stored in the luminescent elements with the reverse bias voltage and which do not contribute to illumination are diminished as compared with those charged in luminescent elements in a known display panel, thus reducing useless power dissipation.
Accordingly, the present invention provides a luminescent display panel drive unit including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and connected to the scanning lines and drive lines and which have polarities, the drive unit comprising:
control means for setting a scanning period during which a single scanning line is selected from the plurality of scanning lines in accordance with a scan timing of an input video signal, for specifying a light-emission drive line assigned to the capacitive luminescent element which is connected to the single scanning line and is to be illuminated in accordance with the input video signal during the scanning period, for setting a reset period during an interval between scanning periods, and for specifying, as a non-reset drive line, at least the drive line having connected thereto the capacitive luminescent element to remain unilluminated during the scanning periods before and after the reset period;
scanning means for applying a first potential lower than an illumination threshold voltage of the capacitive luminescent element to the single scanning line during the scanning period, for applying a second potential higher than the illumination threshold voltage to scanning lines other than the single scanning line, and for applying the second potential to all the scanning lines during the reset period; and
drive means for supplying a drive current to the illumination drive line for forwardly applying, during the scanning period, a positive voltage higher than the illumination threshold voltage to the capacitive luminescent element to be illuminated, for applying a third potential slightly lower than the illumination threshold voltage to the drive lines other than the illumination drive line, for supplying during the reset period a fourth potential equal to the second potential to the plurality of drive lines exclusive of the non-reset drive line, and for applying the third potential to the non-reset drive line.
According to the present invention, a first potential lower than an illumination threshold voltage is applied to a single scanning line selected for scanning, during a scanning period. A second potential higher than the illumination threshold voltage is applied to the scanning lines other than the single scanning line. A fourth potential slightly lower than the illumination threshold voltage is applied to the plurality of drive lines other than an illumination drive line connected to capacitive luminescent elements to be illuminated. Consequently, a comparatively-low reverse bias voltage is applied to respective capacitive luminescent elements located in intersections between scanning lines except the single scanning line and drive lines except the illumination drive line. Electric charges which are stored in the luminescent elements with the reverse bias voltage and which do not contribute to illumination are diminished as compared with those charged in luminescent elements in a known display panel, thus reducing useless power dissipation.
Further, during the reset period, there is specified as a non-reset drive line at least the drive line connected to the capacitive luminescent element which is to remain unilluminated during the scanning periods before and after the reset period, and the second potential is applied to all the scanning lines. Moreover, a fourth potential equal to the second potential is applied to the plurality of drive lines exclusive of the non-reset drive line, and a third potential is applied to the non-reset drive line. The electric chargesxe2x80x94which are stored in the capacitive luminescent elements connected to a non-reset drive line by means of the reverse bias voltagexe2x80x94are held without being discharged. Even when the reverse bias voltage is applied to the capacitive luminescent elements during the next scanning period, charging or discharging barely arises in the luminescent elements, thereby reducing useless power dissipation.
Further, accordingly, the present invention provides a luminescent display panel drive unit including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and connected to the scanning lines and rive lines and which have polarities, the drive unit comprising:
control means for setting a scanning period during which a single scanning line is selected from the plurality of scanning lines in accordance with a scan timing of an input video signal, for specifying a light-emission drive line assigned to the capacitive luminescent element which is connected to the single scanning line and is to be illuminated in accordance with the input video signal during the scanning period, for setting a reset period during an interval between scanning periods, and for specifying, as anon-reset drive line, only the drive line having connected thereto the capacitive luminescent element to remain unilluminated during the scanning periods before and after the reset period;
scanning means for applying a first potential lower than an illumination threshold voltage of the capacitive luminescent element to the single scanning line during the scanning period, for applying a second potential higher than the illumination threshold voltage to scanning lines other than the single scanning line, and for applying the second potential to all the scanning lines during the reset period; and
drive means for supplying a drive current to the illumination drive line for forwardly applying, during the scanning period, a positive voltage higher than the illumination threshold voltage to the capacitive luminescent element to be illuminated, for applying a third potential slightly lower than the illumination threshold voltage to the drive lines other than the illumination drive line, for supplying during the reset period a fourth potential equal to the second potential to the plurality of drive lines exclusive of the non-reset drive line, and for applying the third potential to the non-reset drive line.
According to the present invention, a first potential lower than an illumination threshold voltage is applied to a single scanning line selected for scanning, during a scanning period. A second potential higher than the illumination threshold voltage is applied to the scanning lines other than the single scanning line. A fourth potential slightly lower than the illumination threshold voltage is applied to the plurality of drive lines other than an illumination drive line connected to capacitive luminescent elements to be illuminated. Consequently, a comparatively-low reverse bias voltage is applied to respective capacitive luminescent elements located in intersections between scanning lines except the single scanning line and drive lines except the illumination drive line. Electric charges which are stored in the luminescent elements with the reverse bias voltage and which do not contribute to illumination are diminished as compared with those charged in luminescent elements in a known display panel, thus reducing useless power dissipation.
Further, during the reset period, there is specified as a non-reset drive line only the drive line connected to the capacitive luminescent element which is to remain unilluminated during the scanning periods before and after the reset period, and the second potential is applied to all the scanning lines. Moreover, a fourth potential equal to the second potential is applied to the plurality of drive lines exclusive of the non-reset drive line, and a third potential is applied to the non-reset drive line. The electric chargesxe2x80x94which are stored in the capacitive luminescent elements connected to a non-reset drive line by means of the reverse bias voltagexe2x80x94are held without being discharged. Even when the reverse bias voltage is applied to the capacitive luminescent elements during the next scanning period, charging or discharging barely arises in the luminescent elements, thereby reducing useless power dissipation.
The present invention also provides a luminescent display panel drive unit including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and connected to the scanning lines and drive lines and which have polarities, the drive unit comprising:
control means for setting a scanning period during which a single scanning line is selected from the plurality of scanning lines in accordance with a scan timing of an input video signal, for specifying a light-emission drive line assigned to the capacitive luminescent element which is connected to the single scanning line and is to be illuminated in accordance with the input video signal during the scanning period, for setting a reset period during an interval between scanning periods, and for specifying, as a non-reset drive line, only the drive line having connected to the capacitive luminescent element to remain unilluminated during the scanning period subsequent to the reset period;
scanning means for applying a first potential lower than an illumination threshold voltage of the capacitive luminescent element to the single scanning line during the scanning period, for applying a second potential higher than the illumination threshold voltage to scanning lines other than the single scanning line, and for applying the second potential to all the scanning lines during the reset period; and
drive means for supplying a drive current to the illumination drive line for forwardly applying, during the scanning period, a positive voltage higher than the illumination threshold voltage to the capacitive luminescent element to be illuminated, for applying a third potential slightly lower than the illumination threshold voltage to the drive lines other than the illumination drive line, for supplying during the reset period a fourth potential equal to the second potential to the plurality of drive lines exclusive of the non-reset drive line, and for applying the third potential to the non-reset drive line.
According to the present invention, a first potential lower than an illumination threshold voltage is applied to a single scanning line selected for scanning, during a scanning period. A second potential higher than the illumination threshold voltage is applied to the scanning lines other than the single scanning line. A fourth potential slightly lower than the illumination threshold voltage is applied to the plurality of drive lines other than an illumination drive line connected to capacitive luminescent elements to be illuminated. Consequently, a comparatively-low reverse bias voltage is applied to respective capacitive luminescent elements located in intersections between scanning lines except the single scanning line and drive lines except the illumination drive line. Electric charges which are stored in the luminescent elements with the reverse bias voltage and which do not contribute to illumination are diminished as compared with those charged in luminescent elements in a known display panel, thus reducing useless power dissipation.
Further, during the reset period, there is specified as a non-reset drive line only the drive line connected to the capacitive luminescent element which is to remain unilluminated during a scanning period subsequent to the reset period, and the second potential is applied to all the scanning lines. Moreover, a fourth potential equal to the second potential is applied to the plurality of drive lines exclusive of the non-reset drive line, and a third potential is applied to the non-reset drive line. The electric chargesxe2x80x94which are stored in the capacitive luminescent elements connected to non-reset drive line by means of the reverse bias voltagexe2x80x94are held without being discharged. Even when the reverse bias voltage is applied to the capacitive luminescent elements during the next scanning period, charging or discharging barely arises in the luminescent elements, thereby reducing useless power dissipation.
Further, the present invention provides a luminescent display panel drive unit including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and are connected to the scanning lines and drive lines and which have polarities, the drive unit comprising:
determination means for distinguishing, as real scanning lines from the plurality of scanning lines, scanning lines which are connected to capacitive luminescent elements to be illuminated during each scanning period;
control means which sequentially specifies one scanning line from the real scanning lines and specifies light-emission drive lines assigned to the capacitive luminescent elements to be illuminated every time one scanning line is specified, the luminescent elements being connected to the specified scanning line; and
drive means for forwardly supplying a drive current to the capacitive luminescent elements to be illuminated, by way of the scanning line and the light-emission drive line every time one scanning line is specified.
Further, the present invention also provides a method of driving a luminescent display panel including
a plurality of drive lines and a plurality of scanning lines, which intersect each other; and
a plurality of capacitive luminescent elements which are provided in respective intersections between the drive lines and the scanning lines and are connected to the scanning lines and drive lines and which have polarities, the method comprising the steps of:
distinguishing, as real scanning lines from the plurality of scanning lines, scanning lines which are connected to capacitive luminescent elements to be illuminated during each scanning period;
sequentially specifying one scanning line from the real scanning lines and specifies light-emission drive lines assigned to the capacitive luminescent elements to be illuminated every time one scanning line is specified, the luminescent elements being connected to the specified scanning line; and
forwardly supplying a drive current to the capacitive luminescent elements to be illuminated, by way of the scanning line and the light-emission drive line every time one scanning line is specified.
By means of the configuration embodied by the present invention, scanning lines to which capacitive luminescent elements to be illuminated are connected are scanned, and the remaining scanning lines are not scanned. Useless power dissipation can be diminished, by the amount corresponding to the power required for scanning the scanning lines to which capacitive luminescent elements to be illuminated are not connected.